"""Support for FRITZ!Box routers."""
import logging

from fritzconnection.core import exceptions as fritzexceptions
from fritzconnection.lib.fritzhosts import FritzHosts
import voluptuous as vol

from homeassistant.components.device_tracker import (
    DOMAIN,
    PLATFORM_SCHEMA,
    DeviceScanner,
)
from homeassistant.const import CONF_HOST, CONF_PASSWORD, CONF_USERNAME
import homeassistant.helpers.config_validation as cv

_LOGGER = logging.getLogger(__name__)

DEFAULT_HOST = "169.254.1.1"  # This IP is valid for all FRITZ!Box routers.
DEFAULT_USERNAME = "admin"

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Optional(CONF_HOST, default=DEFAULT_HOST): cv.string,
        vol.Optional(CONF_USERNAME, default=DEFAULT_USERNAME): cv.string,
        vol.Optional(CONF_PASSWORD): cv.string,
    }
)


def get_scanner(hass, config):
    """Validate the configuration and return FritzBoxScanner."""
    scanner = FritzBoxScanner(config[DOMAIN])
    return scanner if scanner.success_init else None


class FritzBoxScanner(DeviceScanner):
    """This class queries a FRITZ!Box router."""

    def __init__(self, config):
        """Initialize the scanner."""
        self.last_results = []
        self.host = config[CONF_HOST]
        self.username = config[CONF_USERNAME]
        self.password = config.get(CONF_PASSWORD)
        self.success_init = True

        # Establish a connection to the FRITZ!Box.
        try:
            self.fritz_box = FritzHosts(
                address=self.host, user=self.username, password=self.password
            )
        except (ValueError, TypeError):
            self.fritz_box = None

        # At this point it is difficult to tell if a connection is established.
        # So just check for null objects.
        if self.fritz_box is None or not self.fritz_box.modelname:
            self.success_init = False

        if self.success_init:
            _LOGGER.info("Successfully connected to %s", self.fritz_box.modelname)
            self._update_info()
        else:
            _LOGGER.error(
                "Failed to establish connection to FRITZ!Box with IP: %s", self.host
            )

    def scan_devices(self):
        """Scan for new devices and return a list of found device ids."""
        self._update_info()
        active_hosts = []
        for known_host in self.last_results:
            if known_host["status"] and known_host.get("mac"):
                active_hosts.append(known_host["mac"])
        return active_hosts

    def get_device_name(self, device):
        """Return the name of the given device or None if is not known."""
        ret = self.fritz_box.get_specific_host_entry(device).get("NewHostName")
        if ret == {}:
            return None
        return ret

    def get_extra_attributes(self, device):
        """Return the attributes (ip, mac) of the given device or None if is not known."""
        ip_device = None
        try:
            ip_device = self.fritz_box.get_specific_host_entry(device).get(
                "NewIPAddress"
            )
        except fritzexceptions.FritzLookUpError as fritz_lookup_error:
            _LOGGER.warning(
                "Host entry for %s not found: %s", device, fritz_lookup_error
            )

        if not ip_device:
            return {}
        return {"ip": ip_device, "mac": device}

    def _update_info(self):
        """Retrieve latest information from the FRITZ!Box."""
        if not self.success_init:
            return False

        _LOGGER.debug("Scanning")
        self.last_results = self.fritz_box.get_hosts_info()
        return True
